1. Field of the Invention
The present invention relates to the field of plant breeding and, more specifically, to the development of squash line YPC 130-1035T.
2. Description of Related Art
The goal of vegetable breeding is to combine various desirable traits in a single variety/hybrid. Such desirable traits may include greater yield, resistance to insects or pests, tolerance to heat and drought, better agronomic quality, higher nutritional value, growth rate and fruit properties.
Breeding techniques take advantage of a plant's method of pollination. There are two general methods of pollination: a plant self-pollinates if pollen from one flower is transferred to the same or another flower of the same plant or plant variety. A plant cross-pollinates if pollen comes to it from a flower of a different plant variety.
Plants that have been self-pollinated and selected for type over many generations become homozygous at almost all gene loci and produce a uniform population of true breeding progeny, a homozygous plant. A cross between two such homozygous plants of different varieties produces a uniform population of hybrid plants that are heterozygous for many gene loci. Conversely, a cross of two plants each heterozygous at a number of loci produces a population of hybrid plants that differ genetically and are not uniform. The resulting non-uniformity makes performance unpredictable.
The development of uniform varieties requires the development of homozygous inbred plants, the crossing of these inbred plants, and the evaluation of the crosses. Pedigree breeding and recurrent selection are examples of breeding methods that have been used to develop inbred plants from breeding populations. Those breeding methods combine the genetic backgrounds from two or more plants or various other broad-based sources into breeding pools from which new lines are developed by selfing and selection of desired phenotypes. The new lines are evaluated to determine which of those have commercial potential.
One crop species which has been subject to such breeding programs and is of particular value is squash. The term squash is used to refer to four species of the genus Cucurbita of the family Cucurbitaceae: (1) C. maxima, which includes the Hubbard, buttercup, and some large pumpkins, (2) C. mixta, including cushaw squash, (3) C. moschata, which includes the butternut squash, and (4) C. pepo. Acorn squash, zucchini, yellow crookneck and straightneck, and most pumpkins belong to this last species.
The term squash encompasses pumpkins, marrows, and zucchinis. Exclusively ornamental and functional varieties are included among gourds. There is considerable variation in size, shape and color. A typical categorization is to distinguish between summer and winter varieties. Summer squashes include young vegetable marrows, such as zucchini, and are harvested during the summer months. At this stage, the skin of the fruit is tender and the fruit relatively small. Common fruit forms include straightneck, crookneck, saucer shaped, and oblong.
Winter squashes, including Hubbard, butternut and pumpkin, are harvested in late summer/early Fall once the rind has hardened. In contrast to summer squash, winter squash is eaten in the mature fruit stage. In some regions the term ‘winter squash’ is used to refer to mature fruits of the maxima species only.
Many different squash cultivars have been produced, and squash breeding efforts have been underway in many parts of the world (see e.g. U.S. Pat. No. 6,916,974, U.S. Pat. No. 6,414,224, U.S. Pat. No. 5,811,642, U.S. Pat. No. 5,457,278, U.S. Pat. No. 4,713,491). Some breeding objectives include varying the color, texture and flavor of the fruit. Other objectives include optimizing flesh thickness, solid content (% dry matter), and sugar content. Breeding programs have also focused on developing plants with earlier fruit maturity, more restricted vine growth, improved disease resistance or tolerance, and improved adaptability to environmental conditions. In the case of pumpkins, one goal is to produce hull-less seeds for the snack food industry. In the case of summer squash, one of the goals is to develop plants with reduced prickly spines. A parthenocarpic hybrid summer squash has been reported (U.S. Pat. No. 6,031,158).
Advances in biotechnology have resulted in genetically engineered squash with resistance or immunity to some viruses. One of the earliest examples is a squash line having resistance to zucchini yellow mosaic virus and watermelon mosaic virus 2 (Fuchs et al., 1995). Development of transgenic squash that is resistant to SqMV and other viruses has also been reported (Pang et al., 2000; U.S. Pat. No. 6,337,431).
While breeding efforts to date have provided a number of useful squash lines with beneficial traits, there remains a great need in the art for new lines with further improved traits. Such plants would benefit farmers and consumers alike by improving crop yields and/or quality.